// CodeMirror, copyright (c) by Marijn Haverbeke and others
// Distributed under an MIT license: http://codemirror.net/LICENSE

(function(mod) {
  if (typeof exports == 'object' && typeof module == 'object')
    // CommonJS
    mod(
      require('../../lib/codemirror'),
      require('./searchcursor'),
      require('../scroll/annotatescrollbar'),
    );
  else if (typeof define == 'function' && define.amd)
    // AMD
    define([
      '../../lib/codemirror',
      './searchcursor',
      '../scroll/annotatescrollbar',
    ], mod);
  // Plain browser env
  else mod(CodeMirror);
})(function(CodeMirror) {
  'use strict';

  CodeMirror.defineExtension('showMatchesOnScrollbar', function(
    query,
    caseFold,
    options,
  ) {
    if (typeof options == 'string') options = { className: options };
    if (!options) options = {};
    return new SearchAnnotation(this, query, caseFold, options);
  });

  function SearchAnnotation(cm, query, caseFold, options) {
    this.cm = cm;
    this.options = options;
    var annotateOptions = { listenForChanges: false };
    for (var prop in options) annotateOptions[prop] = options[prop];
    if (!annotateOptions.className)
      annotateOptions.className = 'CodeMirror-search-match';
    this.annotation = cm.annotateScrollbar(annotateOptions);
    this.query = query;
    this.caseFold = caseFold;
    this.gap = { from: cm.firstLine(), to: cm.lastLine() + 1 };
    this.matches = [];
    this.update = null;

    this.findMatches();
    this.annotation.update(this.matches);

    var self = this;
    cm.on(
      'change',
      (this.changeHandler = function(_cm, change) {
        self.onChange(change);
      }),
    );
  }

  var MAX_MATCHES = 1000;

  SearchAnnotation.prototype.findMatches = function() {
    if (!this.gap) return;
    for (var i = 0; i < this.matches.length; i++) {
      var match = this.matches[i];
      if (match.from.line >= this.gap.to) break;
      if (match.to.line >= this.gap.from) this.matches.splice(i--, 1);
    }
    var cursor = this.cm.getSearchCursor(
      this.query,
      CodeMirror.Pos(this.gap.from, 0),
      this.caseFold,
    );
    var maxMatches = (this.options && this.options.maxMatches) || MAX_MATCHES;
    while (cursor.findNext()) {
      var match = { from: cursor.from(), to: cursor.to() };
      if (match.from.line >= this.gap.to) break;
      this.matches.splice(i++, 0, match);
      if (this.matches.length > maxMatches) break;
    }
    this.gap = null;
  };

  function offsetLine(line, changeStart, sizeChange) {
    if (line <= changeStart) return line;
    return Math.max(changeStart, line + sizeChange);
  }

  SearchAnnotation.prototype.onChange = function(change) {
    var startLine = change.from.line;
    var endLine = CodeMirror.changeEnd(change).line;
    var sizeChange = endLine - change.to.line;
    if (this.gap) {
      this.gap.from = Math.min(
        offsetLine(this.gap.from, startLine, sizeChange),
        change.from.line,
      );
      this.gap.to = Math.max(
        offsetLine(this.gap.to, startLine, sizeChange),
        change.from.line,
      );
    } else {
      this.gap = { from: change.from.line, to: endLine + 1 };
    }

    if (sizeChange)
      for (var i = 0; i < this.matches.length; i++) {
        var match = this.matches[i];
        var newFrom = offsetLine(match.from.line, startLine, sizeChange);
        if (newFrom != match.from.line)
          match.from = CodeMirror.Pos(newFrom, match.from.ch);
        var newTo = offsetLine(match.to.line, startLine, sizeChange);
        if (newTo != match.to.line)
          match.to = CodeMirror.Pos(newTo, match.to.ch);
      }
    clearTimeout(this.update);
    var self = this;
    this.update = setTimeout(function() {
      self.updateAfterChange();
    }, 250);
  };

  SearchAnnotation.prototype.updateAfterChange = function() {
    this.findMatches();
    this.annotation.update(this.matches);
  };

  SearchAnnotation.prototype.clear = function() {
    this.cm.off('change', this.changeHandler);
    this.annotation.clear();
  };
});
